1. Field of the Invention
This invention relates to fastening apparatus and methods, and more particularly to pneumatically powered stapling methods and apparatuses.
2. Description of the Prior Art
A recurring fastening problem is that presented by the need to mount a sheet of flexible material such as fabric upon a mounting panel or frame. Typical examples of this fastening problem arise in the mounting of handwork, such as crewel work, upon a display panel, mounting of artist's canvas upon stretcher frames, or in the mounting of decorative fabric or posters upon frames. In each situation, the respective pieces must be held in alignment while being fastened together, and it is very difficult to simultaneously maintain alignment, usually under a certain amount of stretching tension, while inserting fasteners through the sheet of material into the mounting panel or frame. The use of machine powered magazine fed fasteners such as staples would be desirable for convenience and speed and because of the uniform gripping force this would provide. However, known staplers and stapler actuating techniques are not suited for workpieces of the type described since they either require the use of the hands in actuation, thereby making it difficult to align and tension the material, or they require the use of another part of the body for actuation, with the result that fastening is slow, or awkward, or uncomfortable, or difficult to coordinate. Moreover, it would be preferable to use known stapling mechanisms with proven reliability and availability at low cost through mass manufacture. In particular, it would be highly desirable to use a pneumatic stapler mechanism of the type commonly used in staple guns mounting insulation or acoustic tiles or the like, and having a finger operated control valve positionable either to connect the pneumatic air supply to the staple driving mechanism to advance the staple driver, or to block the air supply and to retract the staple driver. Heretofore, no satisfactory way has been found for resolving these problems and for inexpensively realizing a reliable and safe method and apparatus suitable for convenient and rapid use with a workpiece such as a hand held panel and a sheet of material to be mounted thereon.